sence ive seen SSOO! damn meny people complain why AVS is SO on a good with an actaully a good video/graphics card, I've got an easy solution:

first get this nice application called: PowerStrip (those who do have it never mind, those who dont you can get it at www.download.com )
secoundly download it and install it easy enough right?

next! make sure powerstrip is running, and right click on that nice new icon in your system tray, then go Display Profiles > Configure > then you should have this pull down bar where it says on default: "Windows Default" (meaning optimal or at least make sure it is on optimal)
change that to "Standard Discrete Timing"
which should able you to change your refresh rate to what your gfx card is able to do (ati radeon 32mb for example can get up to 200mhx refresh rate and that graphics card normal timing engine clock is at defualt at 164mhz!, which of course i overclocked that with powerstrip also )

ok i admit, its not much os a fix but it does give an average gfx card (depending on how much was increased) a good 2-3 fps more, which also depends on the complexity of the preset and on the resolution (or size) of the avs window.